Electric switch.



PATENTED FEB. 28, 1 905.

W. H. POWELL.

ELECTRIC SWITCH.

APPLICATION FILED 00124, 1904.

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Witnesses;

522 :1314 H- Powell Afforr g/t No. 783,981. PATENTED FEB. 28,1905.

W. H. POWELL. I

ELECTRIC SWITCH.

APPLICATION FILED OCT. 24, 1904.

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Patented February 28, 1905.

UNITED STATES PATENT OEEIcE.

lVILLIAM H. POWVELL, OF EAST ORANGE, NElV JERSEY, ASSIGNOR TO OROCKERJVHEELER COMPANY, OF AMPERE. NEW JERSEY, A COR- PORATION OF NEW JERSEY.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 783,981, dated February 28, 1905.

Application filed October 24, 1904. Serial No. 229,741.

To all whom, it ntay concern:

Be it known that I, VILLIAM H. POWELL, a citizen of the United States of America, and a resident of East Orange, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

This switch has been devised for the rheostatic control and reversal of electric motors, and is particularly applicable in conditions where it is desired to run the-motor in either direction and to provide a considerable number of control-points, the two classes of control being effected by the operation of a unitary rotatable member preferably of the drum type,u pon which suitable contacts are mounted and brought into contact with contact-fingers ranged along the side of the drum. In switches of this character, particularly when they operate a rheostatic control, as many contactfingers are required as there are control positions for effecting the rheostat connections in addition to the fingers for the reverser-con tacts and the fingers for effecting multiple breaks in the circuit in passing to the off position. \Vith separate contact-rings on the controller-drum for each finger, a drum and switch of excessive length is required, particularly if there are a considerable number of control positions.

The object of this invention is to avoid such excessive length of switch by placing the contact-fingers for the control positions in two switch-cylinder, together with a diagram ol the connections. showing the arrangementl or motor regulation by rheostatic variation ol the armature-current.

Fig. 4: is a develop- .to 14C of the switch.

drum diametrically opposite to the element along which the first row is contacting at the same time. The contacts on the drum and the lingers cooperating with them may be classi lied according to use into three groups for multiple breaking, rheostatic control, and reversal. The first group has contacts I and 1*, which contact with the fingers L and R, and thereby connect one end of a series of resistances w to 0' to the line. The purpose of this ring of contacts and fingers is to introduce two additional breaks in the circuit and out off the resistance from the line L when the switch is brought to the ofif position in which it is illustrated. The second group has contacts Z" to 73, which contact with the fingers R to l leading from the resistance and connects in or cuts out the sections of the resistance, as required, at the different control positions 1 The third group has contacts a, (m, s, and a, which contact with the fingers A, AA, S, and S to efi'ect reversal in the circuit connections through the armature when the switch is thrown from one side to the other of the oll position. The contact (1/ is in electrical connection with the contaets 711 to 7" of the second group through the bases on which these contacts are supported and attached to the core. The contacts (11/, x, and s are likewise connected.

The contacts for the rheostatic control are placed on the controller drum along two spiral lines, hall in each spiral, one spiral with the contacts 7c to Z being right-hand and the other spiral with the contacts 2 to Z being left-hand. These spirals and the contacts composing them are symmetrically disposed on the drum with respect to the element 1/ o,

which is the element that lies opposite one of the rows of lingers, L, R to R A, and S, when the controller is at the off position and represents the off position of the switch-drum with respect to this row of fingers. Italso follows that the spirals and the contacts composing them are symmetrically disposed with respect to the diametrically opposite element 0 0 of the drum, and as this lies opposite the other row of lingers, R, R to R, and AA, when the controller is in the off postion, this element represents the oli position of switch-drum, with respect to this second row of lingers.

The drum-contacts are so placed that they will make contact with the eontact-lingers in proper sequence and that the sequence shall be the same for either direction of movement from the olf position. In order that this may be possible with two lingers and two contacts on each ring of the drum, the lingers which belong to the same group must each be so placed that the linger with which contact is last made, as R, is opposite the linger with which contact is first made, as It, and the linger with which contact is made next to last, as 1- is opposite the finger with which contact is made second, as R so that if the lingers in one row are in sequence from top to bottom the lingers in the other row will be in reverse sequence. As the purpose of the contacts in the application illustrated is to short-circuit additional sections of resistance as the switch is turned toward a full running position, the leading edge of each contact has to be positioned just over the element of the drum at which contact is to be made; but owing to the duplicate use of the contact in making connections the opposite edge of each contact becomes the leading edge to be properly positioned on operating the switch toward the reverse running position. The width of each of the contacts is therefore determined by the distance apart of the leading edges and this in turn is regulated by the departure from symmetry of the controller positions 1 and 14, at which contact is made with the first and last contact-fingers of the group. If position 14 were the same angular distance from the element a a that position 1 is from the element 0 0, so that the two would be in symmetry, then each contact would. have to be narrow enough to lie across but one positional element of the drum. This is insuificient, and in order that the contacts may be wider the circle is so subdivided that the position 14 will be at a greater angular distance from the element 1/ 0 than the angular distance between position 1 and the element 0 o, with position 14, which is the end position for one direction of movement coinciding with position 2 for the contrary direction of movement. As illustrated, the two end positions at which contact is made with the group of armature rheostat-tingers are out of symmetry with each other by the angular space of consecutive positions and under these conditions each contact will lie across two positional elements.

As the contacts in either group, as b to U, efl'ect controller changes at different angular positions of the drum from the angular positions at which controller changes are elfected by any of the contacts of the other group of contacts, 7: to 71 it follows that the angular distances of the contacts 7: to 7'; from the contact-lingers R to R are different from the angular distances of the contact-lingers 11 to Z1 from the contact-lingers R to R and this is true not only when the switch is in the ofl position, but also when the switch is in any operative position, since operation of the switch to any position adds to or subtracts from all the angles to an equal extent and does notdisturb their inequality.

In the modilied arrangement of Fig. 4 it is not necessary to have the first and last actual controller positions 1 and 13 out of syl'nmetry in order to give sufiicient width or length to the contacts Z" to Z1, since these contacts are brought into and out of contact at positions 1 to 8, these being the end positions with respect to the contact-lingers of this group, and since they are live divisions out of symmetry these contacts are extended over the spaces between live positions. This modilied arrangement also illustrates an arrangement of lingers and contacts for control by variation of the lield strength between positions 8 and 13, in which the lingers F to F and contacts j to j are likewise grouped in two rows in accordance with my invention. The purpose of these contacts is reversely to those of the other group and is to cut in resistance into a circuit as the switch is moved toward the full-runningposition. Hencetheleavingedge of each contact has to be positioned just back of the element of the drum at which additional resistance is to be cut in, and that there may be sufficient length to each contact advantage is taken of the fact that the end positions at which this group is used are out of symmetry reversely to the end positions for the other group.

It will be seen that the positions of the contacts as above delined in reality apply to substantially the positions of the advancing or leaving edges accordingly as the controller changes are effected at either of the above edges.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In an electric controlling-switch, a rotatable member, two sets of contacts carried thereby and symmetrically disposed with respect to a plane through the axis of the rotatable member, and two sets of contact-fingers disposed on opposite sides of the rotatable member, each contact-linger lying in the path of a contact in each set of symmetrically-disposed contaets on the rotatable member, and each of the symmetrically-disposed contacts havingapath ofmovementpastacontact-linger in each set of contact-fingers, the relative positions of the contacts and contact-fingers being such that the angular distances from one set of contacts to one set of contact-fingers will be diflerent from the angular distances of the other set of contacts from the other set of contact-fingers at any angular position of the switch, substantially as described.

2. In an electric controlling-switch, a rotatable switch-cylinder, tWo sets of contacts carried thereby and symmetrically disposed with respect to a plane through the axis of the cylinder, and two sets of contact-fingers disposed on opposite sides of the cylinder, each contact-finger lying in the path of a contact in each set of symmetrically-disposed contacts on the cylinder, and each of the symmetricallydisposed contacts having a path of movement past a contact-finger in each set of contactfingers, the relative positions of the contacts and contact-fingers being such that the angular distances from one set of contacts to one set of contact-fingers will be different from the angular distances of the other set of contacts from the other set of contact-fingers at any angular position of the switch, substantially as described.

3. In an electric controlling and reversing switch a rotatable member, contacts for effecting a reversal of electrical connections carried thereby, two sets of contacts carried thereby and symmetrically disposed with respect to a plane through the axis of the rotatable member, contact-fingers cooperating with the contacts for effecting reversal, and two sets of contact-fingers disposed on diametrically opposite sides of the rotatable member, each contact-finger lying in the path of a contact in each set of symmetrically-disposed contacts on the rotatable member, and each of the symmetrically-disposed contacts having a path 01 movement past a contact-finger in each set of contact-fingers, the relative positions of the contacts and contact-fingers being such that the angular distances from one set of contacts to one set of contact-lingers will be diflerent from the angular distances of the other set of contacts from the other set of contact-lingers at any angular position of the switch, substantially as described.

Signed by me at East Orange, New Jersey, this 29d day of October, 190%.

\VILLIAM H. POlVELL.

\Vitnesses:

SAMUEL XV. BALen, EDWIN it. DOUGLAS. 

